Field of the Invention
The present invention relates to a lithography apparatus, a determination method, and a method of manufacturing an article.
Description of the Related Art
An exposure apparatus which transfers a mask pattern onto a substrate is one of apparatuses to be used in a manufacturing step (lithography step) of a semiconductor device or the like. In the exposure apparatus, a global alignment method is generally used as a method of alignment between a mask and the substrate. In the global alignment method, alignment is performed by detecting the positions of some representative shot regions (sample shot regions) formed on the substrate and using an index obtained by statistically processing the detection result and used as a common index in all the shot regions on the substrate. Japanese Patent Laid-Open No. 2005-217092 has proposed, for an increase in throughput, a method of determining the detection order of sample shot regions so as to reduce the moving distance of a substrate stage between the end of position detection of the sample shot regions and the start of exposure of the sample shot regions.
In general, the exposure apparatus includes a measurement unit (for example, an interferometer) which irradiates the side surface of the substrate stage with light and measures the position of the substrate stage based on reflected light, and controls the movement of the substrate stage based on a measurement result by the measurement unit. If a temperature distribution occurs on an optical path of light emitted from the measurement unit due to the influence of heat generated as the movement of the substrate stage, an error may occur in the measurement result by the measurement unit. Then, if such an error occurs while detecting the position of each sample shot region, it may become difficult to accurately obtain the common index used in all the shot regions on the substrate.